The present invention relates a flasher type fish sonar for displaying data of fish sonar and for flashing letters.
In prior flasher type fish sonar, a display disk comprises a circular window formed at a front of a case, and a luminous body is mounted on a rotary disk opposite to the circular window. The rotary disk is rotated by a motor, slip rings are attached to a rotary shaft of the rotary disk, and brushes contact with the slip rings. An input circuit is connected to the brushes, a control circuit is connected to the input circuit, and an oscillating circuit and a receiving circuit are connected to the control circuit and an ultrasonic transducer.
When oscillating signals are input from the control circuit to the oscillating circuit, oscillating outputs are input from the oscillating circuit to the ultrasonic transducer, and ultrasonic waves are emitted from the ultrasonic vibrator to the water. Reflected ultrasonic waves from the water are received by the ultrasonic transducer, and reflected signals from the ultrasonic transducer are amplified by the receiving circuit and are input from the control circuit to the input circuit. By the reflected signals applied to the input circuit, luminous power is input to the luminous body through the brushes and slip rings from the input circuit. A portion A displayed on the circular window is a start point of a luminosity which shows a surface of the sea, a portion B shows fish, a portion C shows a first bottom echo of the sea, and a portion D shows a second bottom echo of the sea. When signals of letters are input by a keyboard, the control circuit converts the signals of letters to display signals which is input to an input device and letter signals are flashed from the circular window of the display board of the display device.
In the prior flasher type fish sonar, because the signals of the ultrasonic transducer of the fish sonar are displayed on the circular window of the display device and the letters signals are displayed on the same circular window of the display device, the display of the fish sonar and the display of letter signals are difficult to see. It is therefore desired that the display of the fish sonar and the display of the letter signals will be displayed at different portions of the display device.